Multi-INstrument Burst ARchive

This page describes the Multi-INstrument Burst ARchive (MINBAR) data release 1, comprising analyses of thermonuclear (type-I) X-ray bursts observed by the Rossi X-ray Timing Explorer (RXTE), BeppoSAX and INTEGRAL.

Here we describe the columns for each of the source tables.

Bursts | Observations | Burst sources
Bursts

The burst table contains analysis results for every RXTE/PCA, BeppoSAX/WFC and INTEGRAL/JEM-X burst from 85 sources drawn from the source list, detected in the observations making up the observation table. As we list each detected event separately, and 28 bursts were detected by more than one instrument, the burst table includes 7111 entries. The sample of bursts that is queried via the web interface includes approximately 1600 additional events not provided in the ASCII tables; these include type-II events (from the Rapid Burster, observed with the RXTE/PCA), and events initially identified as burst candidates, but subsequently rejected due to the lack of evidence for cooling, or identification with other mechanisms. The selection criterion to retrieve only the events also found in the ASCII table is type=1.

Web tableASCII table
ColumnattributeFormatUnits Description
1 name A23 Likely burst origin
2 instr A3 Instrument label
3 obsid A20 Observation ID
4 time F11.5 d Burst start time (MJD UT)
5 entry I4 MINBAR burst ID
6 entry_obs I6 MINBAR observation ID in which this burst falls
7 bnum I3 Order of the event within the observation
8 xref I3 Burst ID in external catalog (G08 or C17)
9 mult I1 Number of MINBAR instruments which detected this event
10 angle F6.2 arcmin Angle between the source position and pointing axis
11 vigcorr F5.3 Vignetting correction factor
12 sflag A11 Data quality/analysis flags
13 rexp A1 Photospheric radius expansion flag
14 rise F5.2 s Rise time
15 tau F5.1 s Ratio of fluence to peak flux, \tau=Eb/Fpeak
16 taue F5.1 s Uncertainty on \tau
17 dur F6.1 s Burst duration
18 dure F6.1 s Uncertainty on burst duration
19 edt F6.1 s Exponential decay timescale
20 edte F7.3 s Uncertainty on exponential decay timescale
21 tdel F8.1 hr Time since previous burst from this source
22 trec F7.1 hr Inferred recurrence time Trec
23 perflx F6.3 10-9 erg cm-2 s-1 Persistent 3--25 keV flux prior to the burst, Fper
24 perflxe F5.3 10-9 erg cm-2 s-1 Uncertainty on persistent flux
25 alpha F6.1 Ratio of integrated persistent flux to burst fluence, \alpha
26 alphae F6.1 Uncertainty on \alpha
27 bc F5.3 Bolometric correction adopted for persistent flux
28 bce F5.3 Uncertainty on bolometric correction
29 gamma F6.4 Ratio of persistent flux to peak PRE burst flux, \gamma
30 sc F6.3 Soft colour
31 hc F6.3 Hard colour
32 s_z F6.3 Position on colour-colour diagram, Sz
33 pflux F6.2 count s-1 cm-2 Peak photon flux
34 pfluxe F5.2 count s-1 cm-2 Uncertainty on peak photon flux
35 fluen F8.3 count cm-2 Integrated photon flux
36 fluene F7.3 count cm-2 Uncertainty on integrated photon flux
37 bpflux F6.2 10-9 erg cm-2 s-1 Bolometric peak flux Fpeak
38 bpfluxe F5.2 10-9 erg cm-2 s-1 Uncertainty on bolometric peak flux
39 kT F4.2 keV Blackbody temperature kT at burst peak
40 kTe F4.2 keV Uncertainty on kT at burst peak
41 rad F6.1 km/10 kpc Blackbody normalisation at burst peak
42 rade F5.1 km/10 kpc Uncertainty on blackbody normalisation at burst peak
43 bfluen F6.4 10-6 erg cm-2 Bolometric fluence (integrated bolometric flux) Eb
44 bfluene F6.4 10-6 erg cm-2 Uncertainty on bolometric fluence
45 refs A20 References for the burst

Observations

The complete list of observations from which the MINBAR sample was drawn (including non-detections) is only available via this web interface. The additional observations include those in which the target (or any other source in the FOV, in the case of RXTE/PCA) is not detected above our significance threshold; duplicate entries, added in error; and observations from sources in which bursts have not been detected by any of the instruments analysed here, earlier than the cutoff date. The selection criteria to retrieve only the events also found in the ASCII observations table is flag>=0,sig>=3.

Web tableASCII table
ColumnattributeFormatUnits Description
1name A23 Source name
2instr A6 Instrument label
3obsid A20 Observation ID
4entry I6 MINBAR observation ID
5sflag A3 Data quality/analysis flags
6tstart F11.5 MJD Observation start time
7tstop F11.5 MJD Observation stop time
8exp I6 s Total exposure
9angle F7.2 arcmin Off-axis angle
10vigcorr F5.3 Vignetting correction factor
11nburst I3 Number of (type-I) bursts in the observation
12count F8.3 count cm-2 s-1 Background-subtracted mean rate for target source
13counte F8.3 count cm-2 s-1 Uncertainty on mean rate
14sig F6.1 Detection significance for this observation
15flux F6.3 10-9 erg cm-2 s-1 Mean flux over the observation
16fluxe F6.3 10-9 erg cm-2 s-1 Estimated uncertainty on mean flux
17gamma F6.4 \gamma ratio of persistent flux to mean peak flux of radius-expansion bursts
18sc F6.3 Soft colour
19hc F6.3 Hard colour
20s_z F6.3 Sz value, giving position in the colour-colour diagram
21model A30 Spectral model ({\sc XSpec} syntax)
par1 Spectral parameter 1; order in ASCII file varies
par1e Error on spectral parameter 1
par2 Spectral parameter 2; order in ASCII file varies
par2e Error on spectral parameter 2
par3 Spectral parameter 3; order in ASCII file varies
par3e Error on spectral parameter 3
par4 Spectral parameter 4; order in ASCII file varies
par4e Error on spectral parameter 4
par5 Spectral parameter 5; order in ASCII file varies
par5e Error on spectral parameter 5
par6 Spectral parameter 6; order in ASCII file varies
par6e Error on spectral parameter 6
par7 Spectral parameter 7; order in ASCII file varies
par7e Error on spectral parameter 7
par8 Spectral parameter 8; order in ASCII file varies
par8e Error on spectral parameter 8
par9 Spectral parameter 9; order in ASCII file varies
par9e Error on spectral parameter 9
44chisqr F5.2 Mean reduced \chi^2 of spectral fits
45chisqre F5.2 Standard deviation of reduced \chi^2 from spectral fits, where more than one spectrum is fit

Burst sources

We assembled a complete list of thermonuclear burst sources by first cross-matching the INTEGRAL source catalog (Bird et al. 2010; see also here) with the burst sources (source type code "B") in the catalog of LMXBs of Liu et al. (2007). To ensure completeness, we cross-matched our original list with a separate catalog, assembled following a systematic search through the literature and incorporating new discoveries since the mid 1990s (available here).

The resulting sample includes 113 known LMXBs which have exhibited type-I (thermonuclear) bursts. Selected columns in the FITS file which we also provide as part of the MINBAR sample are described below.

Note that the table displayed via the web interface includes three additional columns; the first, a link to the source at Simbad; the second, "bursts" links to a query for all the MINBAR bursts for that source; and the third, "obs" to all the observations.

Web tableFITS table
ColumnattributeFormatUnits Description
1 NAME A22 Burster name
6 Type A7 Source type, as for Table \ref{tab:bursters}
8 RA_OBJ E deg Source right ascension
9 DEC_OBJ E deg Source declination
10 ERR_RAD E deg Positional error
16 NH E 1022 cm-2 Adopted neutral column density NH along the line of sight
17 NH_err D 1022 cm-2 1\sigma uncertainty on NH
18 NH_bibcode A21 Reference bibliographic code for NH value, providing a link to the publication on NASA's ADS
20 COMMENTS A132 Aliases, host clusters, and other information
23 Porb D h Orbital period, where known
24 Porb_flag A1 A "?" indicating cases for which the orbital period is a candidate only
25 Porb_bibcode A21 Bibliographic code for orbital period
57 Vmag E mag V-magnitude, where measured (from Liu et al. 2007)
60 nburst I Number of bursts in MINBAR
61 nobs I Number of observations in MINBAR
62 exp E ks Total exposure
63 ERR_CONF E Confidence level for positional error
64 pos_method A20 Method by which source position determined
65 pos_bibcode A21 Reference for source position
67 disc A6 Instrument and year of discovery of burst activity
68 disc_bibcode A19 Reference bibliographic code for burst discovery
70 rate E hr-1 Burst rate (or limit) measured in the MINBAR sample